diff options
| -rw-r--r-- | arch/Kconfig | 10 | ||||
| -rw-r--r-- | arch/arm/mach-bcm2835/bcm2835.c | 5 | ||||
| -rw-r--r-- | arch/metag/kernel/irq.c | 52 | ||||
| -rw-r--r-- | arch/parisc/kernel/irq.c | 17 | ||||
| -rw-r--r-- | arch/powerpc/Kconfig | 1 | ||||
| -rw-r--r-- | arch/powerpc/kernel/irq.c | 17 | ||||
| -rw-r--r-- | arch/s390/kernel/irq.c | 52 | ||||
| -rw-r--r-- | arch/sh/kernel/irq.c | 57 | ||||
| -rw-r--r-- | arch/sparc/kernel/irq_64.c | 31 | ||||
| -rw-r--r-- | arch/x86/Kconfig | 1 | ||||
| -rw-r--r-- | arch/x86/kernel/entry_64.S | 4 | ||||
| -rw-r--r-- | arch/x86/kernel/i8259.c | 3 | ||||
| -rw-r--r-- | arch/x86/kernel/irq_32.c | 30 | ||||
| -rw-r--r-- | arch/x86/kernel/irq_64.c | 21 | ||||
| -rw-r--r-- | drivers/irqchip/irq-bcm2835.c | 22 | ||||
| -rw-r--r-- | include/linux/interrupt.h | 11 | ||||
| -rw-r--r-- | include/linux/irqchip/bcm2835.h | 29 | ||||
| -rw-r--r-- | kernel/softirq.c | 37 |
18 files changed, 145 insertions, 255 deletions
diff --git a/arch/Kconfig b/arch/Kconfig index af2cc6eabcc7..ad95133f8fae 100644 --- a/arch/Kconfig +++ b/arch/Kconfig @@ -390,6 +390,16 @@ config HAVE_UNDERSCORE_SYMBOL_PREFIX Some architectures generate an _ in front of C symbols; things like module loading and assembly files need to know about this. +config HAVE_IRQ_EXIT_ON_IRQ_STACK + bool + help + Architecture doesn't only execute the irq handler on the irq stack + but also irq_exit(). This way we can process softirqs on this irq + stack instead of switching to a new one when we call __do_softirq() + in the end of an hardirq. + This spares a stack switch and improves cache usage on softirq + processing. + # # ABI hall of shame # diff --git a/arch/arm/mach-bcm2835/bcm2835.c b/arch/arm/mach-bcm2835/bcm2835.c index d50135be0c20..70f2f3925f0e 100644 --- a/arch/arm/mach-bcm2835/bcm2835.c +++ b/arch/arm/mach-bcm2835/bcm2835.c @@ -14,7 +14,7 @@ #include <linux/delay.h> #include <linux/init.h> -#include <linux/irqchip/bcm2835.h> +#include <linux/irqchip.h> #include <linux/of_address.h> #include <linux/of_platform.h> #include <linux/clk/bcm2835.h> @@ -130,8 +130,7 @@ static const char * const bcm2835_compat[] = { DT_MACHINE_START(BCM2835, "BCM2835") .map_io = bcm2835_map_io, - .init_irq = bcm2835_init_irq, - .handle_irq = bcm2835_handle_irq, + .init_irq = irqchip_init, .init_machine = bcm2835_init, .restart = bcm2835_restart, .dt_compat = bcm2835_compat diff --git a/arch/metag/kernel/irq.c b/arch/metag/kernel/irq.c index 2a2c9d55187e..3b4b7f6c0950 100644 --- a/arch/metag/kernel/irq.c +++ b/arch/metag/kernel/irq.c @@ -159,44 +159,30 @@ void irq_ctx_exit(int cpu) extern asmlinkage void __do_softirq(void); -asmlinkage void do_softirq(void) +void do_softirq_own_stack(void) { - unsigned long flags; struct thread_info *curctx; union irq_ctx *irqctx; u32 *isp; - if (in_interrupt()) - return; - - local_irq_save(flags); - - if (local_softirq_pending()) { - curctx = current_thread_info(); - irqctx = softirq_ctx[smp_processor_id()]; - irqctx->tinfo.task = curctx->task; - - /* build the stack frame on the softirq stack */ - isp = (u32 *) ((char *)irqctx + sizeof(struct thread_info)); - - asm volatile ( - "MOV D0.5,%0\n" - "SWAP A0StP,D0.5\n" - "CALLR D1RtP,___do_softirq\n" - "MOV A0StP,D0.5\n" - : - : "r" (isp) - : "memory", "cc", "D1Ar1", "D0Ar2", "D1Ar3", "D0Ar4", - "D1Ar5", "D0Ar6", "D0Re0", "D1Re0", "D0.4", "D1RtP", - "D0.5" - ); - /* - * Shouldn't happen, we returned above if in_interrupt(): - */ - WARN_ON_ONCE(softirq_count()); - } - - local_irq_restore(flags); + curctx = current_thread_info(); + irqctx = softirq_ctx[smp_processor_id()]; + irqctx->tinfo.task = curctx->task; + + /* build the stack frame on the softirq stack */ + isp = (u32 *) ((char *)irqctx + sizeof(struct thread_info)); + + asm volatile ( + "MOV D0.5,%0\n" + "SWAP A0StP,D0.5\n" + "CALLR D1RtP,___do_softirq\n" + "MOV A0StP,D0.5\n" + : + : "r" (isp) + : "memory", "cc", "D1Ar1", "D0Ar2", "D1Ar3", "D0Ar4", + "D1Ar5", "D0Ar6", "D0Re0", "D1Re0", "D0.4", "D1RtP", + "D0.5" + ); } #endif diff --git a/arch/parisc/kernel/irq.c b/arch/parisc/kernel/irq.c index 501ac8b4dcdf..8ceac4785609 100644 --- a/arch/parisc/kernel/irq.c +++ b/arch/parisc/kernel/irq.c @@ -495,22 +495,9 @@ static void execute_on_irq_stack(void *func, unsigned long param1) *irq_stack_in_use = 1; } -asmlinkage void do_softirq(void) +void do_softirq_own_stack(void) { - __u32 pending; - unsigned long flags; - - if (in_interrupt()) - return; - - local_irq_save(flags); - - pending = local_softirq_pending(); - - if (pending) - execute_on_irq_stack(__do_softirq, 0); - - local_irq_restore(flags); + execute_on_irq_stack(__do_softirq, 0); } #endif /* CONFIG_IRQSTACKS */ diff --git a/arch/powerpc/Kconfig b/arch/powerpc/Kconfig index 38f3b7e47ec5..b365d5cbb722 100644 --- a/arch/powerpc/Kconfig +++ b/arch/powerpc/Kconfig @@ -138,6 +138,7 @@ config PPC select OLD_SIGSUSPEND select OLD_SIGACTION if PPC32 select HAVE_DEBUG_STACKOVERFLOW + select HAVE_IRQ_EXIT_ON_IRQ_STACK config EARLY_PRINTK bool diff --git a/arch/powerpc/kernel/irq.c b/arch/powerpc/kernel/irq.c index c7cb8c232d2f..ba0165615215 100644 --- a/arch/powerpc/kernel/irq.c +++ b/arch/powerpc/kernel/irq.c @@ -594,7 +594,7 @@ void irq_ctx_init(void) } } -static inline void do_softirq_onstack(void) +void do_softirq_own_stack(void) { struct thread_info *curtp, *irqtp; @@ -612,21 +612,6 @@ static inline void do_softirq_onstack(void) set_bits(irqtp->flags, &curtp->flags); } -void do_softirq(void) -{ - unsigned long flags; - - if (in_interrupt()) - return; - - local_irq_save(flags); - - if (local_softirq_pending()) - do_softirq_onstack(); - - local_irq_restore(flags); -} - irq_hw_number_t virq_to_hw(unsigned int virq) { struct irq_data *irq_data = irq_get_irq_data(virq); diff --git a/arch/s390/kernel/irq.c b/arch/s390/kernel/irq.c index 8ac2097f13d4..bb27a262c44a 100644 --- a/arch/s390/kernel/irq.c +++ b/arch/s390/kernel/irq.c @@ -157,39 +157,29 @@ int arch_show_interrupts(struct seq_file *p, int prec) /* * Switch to the asynchronous interrupt stack for softirq execution. */ -asmlinkage void do_softirq(void) +void do_softirq_own_stack(void) { - unsigned long flags, old, new; - - if (in_interrupt()) - return; - - local_irq_save(flags); - - if (local_softirq_pending()) { - /* Get current stack pointer. */ - asm volatile("la %0,0(15)" : "=a" (old)); - /* Check against async. stack address range. */ - new = S390_lowcore.async_stack; - if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) { - /* Need to switch to the async. stack. */ - new -= STACK_FRAME_OVERHEAD; - ((struct stack_frame *) new)->back_chain = old; - - asm volatile(" la 15,0(%0)\n" - " basr 14,%2\n" - " la 15,0(%1)\n" - : : "a" (new), "a" (old), - "a" (__do_softirq) - : "0", "1", "2", "3", "4", "5", "14", - "cc", "memory" ); - } else { - /* We are already on the async stack. */ - __do_softirq(); - } + unsigned long old, new; + + /* Get current stack pointer. */ + asm volatile("la %0,0(15)" : "=a" (old)); + /* Check against async. stack address range. */ + new = S390_lowcore.async_stack; + if (((new - old) >> (PAGE_SHIFT + THREAD_ORDER)) != 0) { + /* Need to switch to the async. stack. */ + new -= STACK_FRAME_OVERHEAD; + ((struct stack_frame *) new)->back_chain = old; + asm volatile(" la 15,0(%0)\n" + " basr 14,%2\n" + " la 15,0(%1)\n" + : : "a" (new), "a" (old), + "a" (__do_softirq) + : "0", "1", "2", "3", "4", "5", "14", + "cc", "memory" ); + } else { + /* We are already on the async stack. */ + __do_softirq(); } - - local_irq_restore(flags); } /* diff --git a/arch/sh/kernel/irq.c b/arch/sh/kernel/irq.c index 063af10ff3c1..0833736afa32 100644 --- a/arch/sh/kernel/irq.c +++ b/arch/sh/kernel/irq.c @@ -149,47 +149,32 @@ void irq_ctx_exit(int cpu) hardirq_ctx[cpu] = NULL; } -asmlinkage void do_softirq(void) +void do_softirq_own_stack(void) { - unsigned long flags; struct thread_info *curctx; union irq_ctx *irqctx; u32 *isp; - if (in_interrupt()) - return; - - local_irq_save(flags); - - if (local_softirq_pending()) { - curctx = current_thread_info(); - irqctx = softirq_ctx[smp_processor_id()]; - irqctx->tinfo.task = curctx->task; - irqctx->tinfo.previous_sp = current_stack_pointer; - - /* build the stack frame on the softirq stack */ - isp = (u32 *)((char *)irqctx + sizeof(*irqctx)); - - __asm__ __volatile__ ( - "mov r15, r9 \n" - "jsr @%0 \n" - /* switch to the softirq stack */ - " mov %1, r15 \n" - /* restore the thread stack */ - "mov r9, r15 \n" - : /* no outputs */ - : "r" (__do_softirq), "r" (isp) - : "memory", "r0", "r1", "r2", "r3", "r4", - "r5", "r6", "r7", "r8", "r9", "r15", "t", "pr" - ); - - /* - * Shouldn't happen, we returned above if in_interrupt(): - */ - WARN_ON_ONCE(softirq_count()); - } - - local_irq_restore(flags); + curctx = current_thread_info(); + irqctx = softirq_ctx[smp_processor_id()]; + irqctx->tinfo.task = curctx->task; + irqctx->tinfo.previous_sp = current_stack_pointer; + + /* build the stack frame on the softirq stack */ + isp = (u32 *)((char *)irqctx + sizeof(*irqctx)); + + __asm__ __volatile__ ( + "mov r15, r9 \n" + "jsr @%0 \n" + /* switch to the softirq stack */ + " mov %1, r15 \n" + /* restore the thread stack */ + "mov r9, r15 \n" + : /* no outputs */ + : "r" (__do_softirq), "r" (isp) + : "memory", "r0", "r1", "r2", "r3", "r4", + "r5", "r6", "r7", "r8", "r9", "r15", "t", "pr" + ); } #else static inline void handle_one_irq(unsigned int irq) diff --git a/arch/sparc/kernel/irq_64.c b/arch/sparc/kernel/irq_64.c index d4840cec2c55..666193f4e8bb 100644 --- a/arch/sparc/kernel/irq_64.c +++ b/arch/sparc/kernel/irq_64.c @@ -698,30 +698,19 @@ void __irq_entry handler_irq(int pil, struct pt_regs *regs) set_irq_regs(old_regs); } -void do_softirq(void) +void do_softirq_own_stack(void) { - unsigned long flags; - - if (in_interrupt()) - return; - - local_irq_save(flags); + void *orig_sp, *sp = softirq_stack[smp_processor_id()]; - if (local_softirq_pending()) { - void *orig_sp, *sp = softirq_stack[smp_processor_id()]; - - sp += THREAD_SIZE - 192 - STACK_BIAS; - - __asm__ __volatile__("mov %%sp, %0\n\t" - "mov %1, %%sp" - : "=&r" (orig_sp) - : "r" (sp)); - __do_softirq(); - __asm__ __volatile__("mov %0, %%sp" - : : "r" (orig_sp)); - } + sp += THREAD_SIZE - 192 - STACK_BIAS; - local_irq_restore(flags); + __asm__ __volatile__("mov %%sp, %0\n\t" + "mov %1, %%sp" + : "=&r" (orig_sp) + : "r" (sp)); + __do_softirq(); + __asm__ __volatile__("mov %0, %%sp" + : : "r" (orig_sp)); } #ifdef CONFIG_HOTPLUG_CPU diff --git a/arch/x86/Kconfig b/arch/x86/Kconfig index f67e839f06c8..5cd6eea9b7b3 100644 --- a/arch/x86/Kconfig +++ b/arch/x86/Kconfig @@ -123,6 +123,7 @@ config X86 select COMPAT_OLD_SIGACTION if IA32_EMULATION select RTC_LIB select HAVE_DEBUG_STACKOVERFLOW + select HAVE_IRQ_EXIT_ON_IRQ_STACK if X86_64 config INSTRUCTION_DECODER def_bool y diff --git a/arch/x86/kernel/entry_64.S b/arch/x86/kernel/entry_64.S index b077f4cc225a..083da7c2f40d 100644 --- a/arch/x86/kernel/entry_64.S +++ b/arch/x86/kernel/entry_64.S @@ -1342,7 +1342,7 @@ bad_gs: .previous /* Call softirq on interrupt stack. Interrupts are off. */ -ENTRY(call_softirq) +ENTRY(do_softirq_own_stack) CFI_STARTPROC pushq_cfi %rbp CFI_REL_OFFSET rbp,0 @@ -1359,7 +1359,7 @@ ENTRY(call_softirq) decl PER_CPU_VAR(irq_count) ret CFI_ENDPROC -END(call_softirq) +END(do_softirq_own_stack) #ifdef CONFIG_XEN zeroentry xen_hypervisor_callback xen_do_hypervisor_callback diff --git a/arch/x86/kernel/i8259.c b/arch/x86/kernel/i8259.c index 9a5c460404dc..2e977b5d61dd 100644 --- a/arch/x86/kernel/i8259.c +++ b/arch/x86/kernel/i8259.c @@ -312,8 +312,7 @@ static void init_8259A(int auto_eoi) */ outb_pic(0x11, PIC_MASTER_CMD); /* ICW1: select 8259A-1 init */ - /* ICW2: 8259A-1 IR0-7 mapped to 0x30-0x37 on x86-64, - to 0x20-0x27 on i386 */ + /* ICW2: 8259A-1 IR0-7 mapped to 0x30-0x37 */ outb_pic(IRQ0_VECTOR, PIC_MASTER_IMR); /* 8259A-1 (the master) has a slave on IR2 */ diff --git a/arch/x86/kernel/irq_32.c b/arch/x86/kernel/irq_32.c index 4186755f1d7c..8a5bb01dbc0e 100644 --- a/arch/x86/kernel/irq_32.c +++ b/arch/x86/kernel/irq_32.c @@ -149,35 +149,21 @@ void irq_ctx_init(int cpu) cpu, per_cpu(hardirq_ctx, cpu), per_cpu(softirq_ctx, cpu)); } -asmlinkage void do_softirq(void) +void do_softirq_own_stack(void) { - unsigned long flags; struct thread_info *curctx; union irq_ctx *irqctx; u32 *isp; - if (in_interrupt()) - return; - - local_irq_save(flags); - - if (local_softirq_pending()) { - curctx = current_thread_info(); - irqctx = __this_cpu_read(softirq_ctx); - irqctx->tinfo.task = curctx->task; - irqctx->tinfo.previous_esp = current_stack_pointer; - - /* build the stack frame on the softirq stack */ - isp = (u32 *) ((char *)irqctx + sizeof(*irqctx)); + curctx = current_thread_info(); + irqctx = __this_cpu_read(softirq_ctx); + irqctx->tinfo.task = curctx->task; + irqctx->tinfo.previous_esp = current_stack_pointer; - call_on_stack(__do_softirq, isp); - /* - * Shouldn't happen, we returned above if in_interrupt(): - */ - WARN_ON_ONCE(softirq_count()); - } + /* build the stack frame on the softirq stack */ + isp = (u32 *) ((char *)irqctx + sizeof(*irqctx)); - local_irq_restore(flags); + call_on_stack(__do_softirq, isp); } bool handle_irq(unsigned irq, struct pt_regs *regs) diff --git a/arch/x86/kernel/irq_64.c b/arch/x86/kernel/irq_64.c index d04d3ecded62..4d1c746892eb 100644 --- a/arch/x86/kernel/irq_64.c +++ b/arch/x86/kernel/irq_64.c @@ -87,24 +87,3 @@ bool handle_irq(unsigned irq, struct pt_regs *regs) generic_handle_irq_desc(irq, desc); return true; } - - -extern void call_softirq(void); - -asmlinkage void do_softirq(void) -{ - __u32 pending; - unsigned long flags; - - if (in_interrupt()) - return; - - local_irq_save(flags); - pending = local_softirq_pending(); - /* Switch to interrupt stack */ - if (pending) { - call_softirq(); - WARN_ON_ONCE(softirq_count()); - } - local_irq_restore(flags); -} diff --git a/drivers/irqchip/irq-bcm2835.c b/drivers/irqchip/irq-bcm2835.c index 16c78f1c5ef2..1693b8e7f26a 100644 --- a/drivers/irqchip/irq-bcm2835.c +++ b/drivers/irqchip/irq-bcm2835.c @@ -49,9 +49,11 @@ #include <linux/of_address.h> #include <linux/of_irq.h> #include <linux/irqdomain.h> -#include <linux/irqchip/bcm2835.h> #include <asm/exception.h> +#include <asm/mach/irq.h> + +#include "irqchip.h" /* Put the bank and irq (32 bits) into the hwirq */ #define MAKE_HWIRQ(b, n) ((b << 5) | (n)) @@ -93,6 +95,8 @@ struct armctrl_ic { }; static struct armctrl_ic intc __read_mostly; +static asmlinkage void __exception_irq_entry bcm2835_handle_irq( + struct pt_regs *regs); static void armctrl_mask_irq(struct irq_data *d) { @@ -164,17 +168,9 @@ static int __init armctrl_of_init(struct device_node *node, set_irq_flags(irq, IRQF_VALID | IRQF_PROBE); } } - return 0; -} - -static struct of_device_id irq_of_match[] __initconst = { - { .compatible = "brcm,bcm2835-armctrl-ic", .data = armctrl_of_init }, - { } -}; -void __init bcm2835_init_irq(void) -{ - of_irq_init(irq_of_match); + set_handle_irq(bcm2835_handle_irq); + return 0; } /* @@ -200,7 +196,7 @@ static void armctrl_handle_shortcut(int bank, struct pt_regs *regs, handle_IRQ(irq_linear_revmap(intc.domain, irq), regs); } -asmlinkage void __exception_irq_entry bcm2835_handle_irq( +static asmlinkage void __exception_irq_entry bcm2835_handle_irq( struct pt_regs *regs) { u32 stat, irq; @@ -222,3 +218,5 @@ asmlinkage void __exception_irq_entry bcm2835_handle_irq( } } } + +IRQCHIP_DECLARE(bcm2835_armctrl_ic, "brcm,bcm2835-armctrl-ic", armctrl_of_init); diff --git a/include/linux/interrupt.h b/include/linux/interrupt.h index 5e865b554940..c9e831dc80bc 100644 --- a/include/linux/interrupt.h +++ b/include/linux/interrupt.h @@ -19,6 +19,7 @@ #include <linux/atomic.h> #include <asm/ptrace.h> +#include <asm/irq.h> /* * These correspond to the IORESOURCE_IRQ_* defines in @@ -374,6 +375,16 @@ struct softirq_action asmlinkage void do_softirq(void); asmlinkage void __do_softirq(void); + +#ifdef __ARCH_HAS_DO_SOFTIRQ +void do_softirq_own_stack(void); +#else +static inline void do_softirq_own_stack(void) +{ + __do_softirq(); +} +#endif + extern void open_softirq(int nr, void (*action)(struct softirq_action *)); extern void softirq_init(void); extern void __raise_softirq_irqoff(unsigned int nr); diff --git a/include/linux/irqchip/bcm2835.h b/include/linux/irqchip/bcm2835.h deleted file mode 100644 index 48a859bc9dca..000000000000 --- a/include/linux/irqchip/bcm2835.h +++ /dev/null @@ -1,29 +0,0 @@ -/* - * Copyright (C) 2010 Broadcom - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License as published by - * the Free Software Foundation; either version 2 of the License, or - * (at your option) any later version. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License for more details. - * - * You should have received a copy of the GNU General Public License - * along with this program; if not, write to the Free Software - * Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA - */ - -#ifndef __LINUX_IRQCHIP_BCM2835_H_ -#define __LINUX_IRQCHIP_BCM2835_H_ - -#include <asm/exception.h> - -extern void bcm2835_init_irq(void); - -extern asmlinkage void __exception_irq_entry bcm2835_handle_irq( - struct pt_regs *regs); - -#endif diff --git a/kernel/softirq.c b/kernel/softirq.c index d7d498d8cc4f..dacd0ab51df4 100644 --- a/kernel/softirq.c +++ b/kernel/softirq.c @@ -29,7 +29,6 @@ #define CREATE_TRACE_POINTS #include <trace/events/irq.h> -#include <asm/irq.h> /* - No shared variables, all the data are CPU local. - If a softirq needs serialization, let it serialize itself @@ -134,7 +133,6 @@ EXPORT_SYMBOL(local_bh_disable); static void __local_bh_enable(unsigned int cnt) { - WARN_ON_ONCE(in_irq()); WARN_ON_ONCE(!irqs_disabled()); if (softirq_count() == cnt) @@ -149,6 +147,7 @@ static void __local_bh_enable(unsigned int cnt) */ void _local_bh_enable(void) { + WARN_ON_ONCE(in_irq()); __local_bh_enable(SOFTIRQ_DISABLE_OFFSET); } @@ -171,8 +170,13 @@ static inline void _local_bh_enable_ip(unsigned long ip) */ sub_preempt_count(SOFTIRQ_DISABLE_OFFSET - 1); - if (unlikely(!in_interrupt() && local_softirq_pending())) + if (unlikely(!in_interrupt() && local_softirq_pending())) { + /* + * Run softirq if any pending. And do it in its own stack + * as we may be calling this deep in a task call stack already. + */ do_softirq(); + } dec_preempt_count(); #ifdef CONFIG_TRACE_IRQFLAGS @@ -280,10 +284,11 @@ restart: account_irq_exit_time(current); __local_bh_enable(SOFTIRQ_OFFSET); + WARN_ON_ONCE(in_interrupt()); tsk_restore_flags(current, old_flags, PF_MEMALLOC); } -#ifndef __ARCH_HAS_DO_SOFTIRQ + asmlinkage void do_softirq(void) { @@ -298,13 +303,11 @@ asmlinkage void do_softirq(void) pending = local_softirq_pending(); if (pending) - __do_softirq(); + do_softirq_own_stack(); local_irq_restore(flags); } -#endif - /* * Enter an interrupt context. */ @@ -329,15 +332,21 @@ void irq_enter(void) static inline void invoke_softirq(void) { if (!force_irqthreads) { +#ifdef CONFIG_HAVE_IRQ_EXIT_ON_IRQ_STACK /* * We can safely execute softirq on the current stack if * it is the irq stack, because it should be near empty - * at this stage. But we have no way to know if the arch - * calls irq_exit() on the irq stack. So call softirq - * in its own stack to prevent from any overrun on top - * of a potentially deep task stack. + * at this stage. */ - do_softirq(); + __do_softirq(); +#else + /* + * Otherwise, irq_exit() is called on the task stack that can + * be potentially deep already. So call softirq in its own stack + * to prevent from any overrun. + */ + do_softirq_own_stack(); +#endif } else { wakeup_softirqd(); } @@ -771,6 +780,10 @@ static void run_ksoftirqd(unsigned int cpu) { local_irq_disable(); if (local_softirq_pending()) { + /* + * We can safely run softirq on inline stack, as we are not deep + * in the task stack here. + */ __do_softirq(); rcu_note_context_switch(cpu); local_irq_enable(); |